Ch 18 Canopy

Date:  04-13-2023

Number of Hours:  5

Manual Reference:  18

There is a nice RAM mount ball below the IP for my iPad mini. Installed and done, or so I thought.
There were some issues.

That pad is really filling my tight cockpit area and it is always going to have reflections as I need it very flat so the panel is still visually accessible. I needed a Plan B.

What if I could mount the iPad up on the left side, like they do for the left seat in a Boeing or Airbus? It would be out of the way but reasonably accessible.  Yes, the other side would might better but I have the compass in that position.

With some regret I have had to give up my beautiful and very functional wooden canopy handle. I have remade a RAM ball mount and drilled for a long bolt. It is also incorporated into the canopy latch seat. I’ve changed out the round head screw here for an AN3 bolt after cutting the thread a little longer. Goodbye old rosewood handle.

The new combined canopy handle and iPad mount is not fantastic to grab onto. I will work out a technique and probably won’t notice it after a while as an issue. This new pad position is a huge problem solver and space saver.

(3 days later) So I had a rethink and got the old handle back on. The latch section needs a slight tweak but we have proof of concept. It turns out that where the iPad mount goes for viewing does not create the interference problem I thought was there. A little win!

Taken through the canopy protective plastic you can still see how it sits.

The pad can be moved around quite a bit for sun reflection issues and it now has a ball air vent right behind it for cooling. OK for once I got lucky. The impact on outside vision is minimal. I have left the old ball mount above the wheel view window for who knows what.

Of course the new problem is getting power to it without a long lead dangling. It’s always something.

 

 

Date:  12-29-2022

Number of Hours:  9

Manual Reference:  18

Hopefully this is the last lot of mods to the rotary canopy latch. This time there were a couple of issue to address.

The latch was interfering with my arm in the cockpit. This was always going to be an issue as there was just nowhere to put it except at my elbow.

The two parts showing in my hand were in the way. The oblong one was the tensioner that was replaced by the gold coloured screw. This is a much reduced profile.

That was in place to tighten the offset disc you see that has been replaced by a larger disk of green G10 material. I felt there was a problem that if the block became loose, which it tended to do, the catch was more likely to pop open. With a disc and a tapped middle hole that can’t happen. Given the latch, canopy and canopy seals are in their final positions I don’t need that adjustment anyway. It took a while, but definitely heads off a future problem.

Another issue was the crescent that the green disc sits against was bothering my arm with its size and sharp edges at the bottom. Its hard to see in the picture but I have made a radiused curve and reduced the height of that block considerably. Sure less than .5″ but now its not a problem.

Here we are with the canopy closed and the safety stop engaged. I have also reduced the length of the two arms on the latch. Maybe .25″ on both. Again what a difference. The latch is no longer the cockpit problem it was. OK it took two days work! Yes I know, I had to go slowly, fitting and refitting, as I didn’t have a good plan B if I stuffed up.

Then the next day I came back and thought I could get the locking tighter by moving the micro switch 2mm or so. It was ‘just’ inhibiting the last movement of locking. So I fixed that too. Now we have an even more positive lock and of course I have the safety pin as a fail-safe. OK, now I think we are 100% as good as I can make it on this latch!

For now all these extensive mods to a bought product are done and dusted.

 

 

Date:  10-24-2022

Number of Hours:  10

Manual Reference:  no ref

While still waiting for my engine delivery there remains a surprising number of small jobs to do.

Time to finally finish off the canopy seals. I did a huge amount of work on this previously following Nick Ugolini’s post on the subject. Here you can see the black ‘Vee’ seals in place.

A look at the canopy rollover seals.

Here we are up close.

Finally the paper test. The canopy closes just as easily as before the seals but it traps paper that needs a good tug to get through. The final test will be in flight but it does seem to work really well.

OK so not a huge mod. These are James Redmon’s rudder gust locks. I just added some aviation quality wire so I don’t loose the push pins.

I’d hate to drop my canopy lock pin so this got a wire retainer too.

I tried a bunch of things but finally I found some soft round rubber of 3mm diameter to make hatch seals. The red stuff is some cutting board with velcro to keep it in place. The idea is that it will act as a spill tray if any water gets in so the flow is directed away from the avionic plugs and components.

I used aviation quality contact cement and tried to minimise the mess that yellow gunky stuff makes.

The seals are in place, the hatches still close. Now I need to fly through a rain shower to test them. Oh and I need an engine too. I’m starting to run out of these small jobs!

 

 

Date:  11-14-2021

Number of Hours:  30

Manual Reference:  18

Kudos goes to Nick Ugolini for this canopy sealing method. Here’s his blog entry. He does say something about it being a weekend job. There are no weekend jobs on my build if that means it gets finished in a weekend. It MIGHT be finished on a weekend after weeks of work is the usual story.

Here’s Nick’s description:- I have found the V-seal to be incredibly effective. The main problem with most seal systems is over crushing of the seal and using cheap weather stripping to seal the canopy. It means your are ALWAYS fighting the seals to close and lock the canopy, over crushing of the seal, and the mis-matching of the canopy to fuselage causing air leaks where the canopy to longeron distance is too great. Imagine a car door. The door gaps are engineered for the seals. The seals are NOT just haphazardly chosen to fit on to hand made doors after they are made.

First up, make some hard points.

That screw with a washer is one of 4 hardpoints I have put in fore and aft. The idea is that the canopy closes onto a fixed corner and then we have the flexible seal in between.

After several tries I made up plastic pieces the same width as the Vee seal I’ll be using less 30% height. Then I covered sections in release tape and plenty of wax.

Here we are with the canopy closed and epoxy/410 filler oozing out.

After cure this is whats left.

After the first clean up, we are starting to get a base for the rubber seal that is perfectly sized for the variable longeron gap.

This is a bit of the yellow spacer I used. On the front lip it had to be curved in two directions. Then I hot glued it in place.

 

Next up tape and wax. You can see some of the completed inside groove too.

The front edge sealed and waiting for the cure.

After I worked it open and a bit of sandpaper we get a clean result.

This is pretty much the groove done. I won’t mention when the canopy got stuck down so badly I had to cut off one of the canopy latches at the front to work it open. Then I had to make a new canopy latch! This has been a really difficult job over three weeks.

The front edge was challenging.

These long sides had to be cut into the canopy  in places and then built back up.

Overall I still don’t know if this is going to work. The concept is sound.

These ends are interesting. They should seal although maybe there will be a very slight gap that I’ll have to deal with. On the plans canopy it would be a MUCH easier job. I just had to do this ultra wide canopy mod didn’t I?

Its going to look better with a little paint. I still have the seals to put in too!

I’ve now added some grey undercoat. It looks better. After the seals it will need proper speckle topcoat and thats going to be a lot of masking work!

 

 

 

 

 

Date:  10-17-2021

Number of Hours:  6

Manual Reference:  18

This is my second major mod to this rotary latch. Despite being a very clever design that solved a problem for me, it created other issues and was perhaps not mature enough a design for our tiny canard market. The supplier has ceased production. I make no criticism, doing it all again I would go in a different direction.

My lack of side door, large throttle placement and large side window still makes it a good solution.

Here it is with those two worm screws showing. The inner one of them is critical. The outer one just holds on a guidance shaft for the Allen key entry.

Here is the critical screw.

That tiny worm holds the big one place. IF that very small worm, with only 4 threads, slips on the flat part of the big worm. BIG TROUBLE.

In fact I would be locked out of the plane and no way to get in without either smashing the canopy or drilling out  the worm and maybe using an ‘easy out’ to activate the handle on the inside.  No problem if you are already in the plane then you use the canopy handle not the rotary latch to get out.  It is potential lockout that is scary.

What I did was engage a master machinist. We got a longer main Allen key worm and set it in place with a countersunk screw on the end. Then for that side worm screw, we got a longer one and instead of a flat, drilled a side hole so the small worm screw engaged positively into a hole. With two different pitch threads on the big worm it can not undo. The side worm is just a bonus.

I ‘Loctited’ the whole thing together and forgot to take pictures. Sorry. Now it can’t come loose and is 100% positive with zero slip. I have confidence again in the latch.

Date:  11-05-2020

Number of Hours:  5

Manual Reference:  18

After all the prep, time for painting the canopy interior. I’ve put this under ‘canopy’ on this site, maybe it should be under Paint? Maybe no one will ever read this.  Its not all that exciting, just another required step along the way.

With the edges between the clear canopy insides and the frame now good I carefully re-masked the edges.

To get these edges clear I’ve used 3mm wide special line tape from an automotive paint supplier. Then some low residue, I hope, painters tape.

Here’s the grey primer. Of course it shows up every little fault now. Given I’m going for the speckle finish I just didn’t get too fussy and spend another week or two for perfection that wasn’t needed here.

The undercoat grey always looks a little dark.

Once the texture goes on with the white flex in it, everything seems to lighten up.

OK, probably too much paint here. It will work out.

After a day to dry I’ve gone with multiple coats of the satin clear from a rattle can. You can see a bit of shine in the pics. Yes I will be having quite thick foam on the canopy edges. I will sand as required for adhesion. My thoughts were to just get an even finish on for now.

After the satin clear dried I’ve gone hard with the scotchbrite pads to get the shine as dull as possible. This gives a flat even finish and removes some of the roughness.

I have off course removed the line and painters tape, checked the edges which were pretty good and then re-taped for protection. Lets call the canopy interior good and move on.

 

 

Date:  11-01-2020

Number of Hours:  12

Manual Reference:  18

The canopy interior is getting a prep before paint. I’ve peeled back the tape and have a bit of a job on my hands.

First up was to clean up the canopy edges around the two ends. That was only a couple of hours.

Next I had to make some enhancements to my holding device. Pretty rough for sure and I like to make use of any scraps of timber lying around.

Someone who will remain unnamed didn’t really take enough care with the canopy edge to frame intersection. Some gummy tape is at the edge but far worse, epoxy has leaked over the top of the tapes from when the inner rails were glassed.

Days of very, very careful work with the dremel and a tiny chisel has been necessary.

Its hard to see in the photo because the blue tape you see is on the other side of the canopy. This side now has a clean straight line.

Here’s the other side now cleaned up too. Many, many hours have gone by. All you smart people use the best tape and wipe up properly after glass work in this area OK?

There is still more prep to go before painting the interior of the frame. The lions share of the work is however done.

Date:  08-25-2019

Number of Hours:  17

Manual Reference:  18-

After the post cure the canopy was refitted and something seemed to have moved just a little. The canopy line was not quite as perfect as it previously was. Only a millimeter or so, but changed, or maybe it had already changed and I missed it.

It seemed to fit back on OK.

Can you see the canopy line is just a fraction out now?

There seemed to be a little bulge in the canopy frame side too. Maybe it was always there?

What followed was about 11 hours all up playing with that little piece of paper. I found when I sat in the back of the plane I could see the location pin on one side was preventing the canopy from closing an extra .25″ or so. I ended up drilling out the receiver fitting and I’ve ordered a new one.

The next thing was to see where the canopy was now hitting the side preventing a ‘deeper closure. If the paper jammed I needed to sand that area of the frame bottom. Over time I got it closing the missing 0.25″. In fact over a lot of time and a lot of sanding and fiddling all around where the frame touched the fuselage.

Eventually I got the canopy closing a little bit more than before, which means a thinner piece of rubber when I get to doing the seals.

I hadn’t finished the fill and sand at the back here before the post cure either. This is probably a good thing given the ‘slight’ adjustment required.

Here you can see its getting closer again and of course another fill and sand cycle. Its hard to believe I spent the whole weekend just getting my ‘fit’ back again.

Oh and I removed and refitted the canopy hardware too, several times. The canopy latch seems to be working a lot better now. The canopy seems to swing more freely and the pins for the nose hatches slide in better. Maybe it was the post cure magic?

Its Monday night and I’ve spent another day on careful fill and sand. Yes I’ve been working on the nose and hatches at the front of the plane as well.

Both areas will need a few more fill/sand cycles too as I edge closer to the real paint prep work.

Date:  07-31-2019

Number of Hours:  8

Manual Reference:  no ref

More work around the canopy edges and adjustments to the canopy latch.

I have several unfinished edges to deal with that were just bare foam.

I’m doing tiny flox corners and one ply of glass to seal things off.

After a clean up I’m getting cleaner edges and plenty of strength.

Of course after a little work the canopy doesn’t quite close again as it did.

A few more hours work and a plan is slowly forming on how I’m going to seal the front a back of this giant canopy. It really needs this fiddle time so I can get an understanding of what has happened when it doesn’t quite close.

Off to the Rubber shop tomorrow to buy some new sealing strips to try.

Date:  07-25-2019

Number of Hours:  6

Manual Reference:  no ref

I’m using the Wilhelmson canopy latch, but it scares me.

Here it is, installed and working with the ‘remote’ modification.

When the canopy is closed it becomes very tight and locks in a solid fashion. I still can imagine in turbulence I might knock it and then bad things could happen.

I needed a solution that would provide a secondary lock. It needed to be something that could only be latched from the inside by the pilot. It had to be something that could not be actuated accidentally from the outside and lock me out of the plane. This is kinda important.

In the end I found a simple or I’d like to say, elegant solution. I can’t say that of course,  this is for others to comment on.

It turned out to be a locking pin from a boat shop. I had an ‘EZ fitting’ for a bolt or screw. I drilled out the thread and cut two slots for the locking ball bearings as you see above.

The next problem was if I just put the fitting into the fuselage wall it was deep enough to perforate the fuel tanks in the strakes. Here is my solution. Just a piece of foam to offset the locking pin from the side wall.

Of course I needed to get excited and epoxy it in place and then add glass and epoxy to bond it to the wall.

With the pin removed normal rotation is required to actuate the lock and open the canopy, the arm has to rotate freely.

With the pin in place the arm can not rotate and the canopy will stay locked. I’m thinking a bit of string is all I need now so the pin doesn’t get lost. Definitely old school here.

With the pin out the handle can move full range. I’m happy with this ‘pilot in place only’ canopy lock as a secondary safeguard. The canopy opening in flight is mitigated by the plans safety catch canopy lock as well. My solution is to address my own lack of comfort in the very clever Wilhelmson lock solution.

Date:  07-22-2019

Number of Hours:  3

Manual Reference:  no ref

A long time ago, like another lifetime, I ordered some chisels from Lewis Luthier Supplies in Canada.

This was the mid seventies, I was just beginning a career as a guitar maker and repairer. I needed good quality tools and earned money working for Skilled Engineering as a boiler attendant. That was a qualification I gained though contacts and then an oral exam. Really old school. All a part of the plan to use part time work while I was building my guitar related skills. I’m still big on plans.

It was a quite a thing in those days to order from overseas needing bank drafts and of course snail mail and very long waits between contacting people.. Yes there was life and commerce before the internet. I remember getting a spare handle with the order but I’d never used it…until now.

I’ve cut down this beautiful Brazilian rosewood handle and added a steel insert with a 3/16″ ID for accepting an AN3-24A bolt. It was the pick of my handle collection.

Here it is installed in the plane as my canopy handle. It is super secure and I may be hanging on to it during severe turbulence.  It is certainly strong enough to use moving my rather heavy canopy open and closed from the inside.

Date:  07-12-2019

Number of Hours:  14

Manual Reference:  no ref

Time to ‘refit’ the canopy.

Its been a while since I had the canopy on. It was never a perfect fit or rather it was pretty good but didn’t close easily and perfectly.

The other issue was that I had set it at less than 90 degrees which turns out to be a problem. It makes getting in and out harder for me, the pilot. The canopy needs to be 90 degrees or more.

Getting this extra few degrees is a major problem. I had two willing helpers as the canopy had to come on and off numerous times. Each iteration I removed a little more filler and increased the gap in the middle section edge between the two hinges. The canopy curves and in the center it needed a lot of clearance before it wouldn’t touch anywhere.

Some time later that night and into the next day I decided on a .5″ gap to the strake and I still had my slightly greater than 90 degree opening.

Now the opening was greater I needed a new strut position or a new gas strut. I went for both in the end. It turns out that while I had imported my gas strut from the USA via Aircraft Spruce, when I wanted a new one, the factory to my surprise was 10 minutes away by car here in Melbourne!  The brand is ‘Stabilus’  and the guys were incredibly helpful and great to deal with.

I got my new strut and had to move the attachment point slightly ‘higher’ with the longer strut. The canopy now opens and closes better than it ever has and I am extremely happy with it. The challenge still to come is to be just as happy with the canopy hardware.  Yes, I will get on to that very soon.